copper(II) complex raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-17. Anything still debated is marked as such rather than presented as settled.
The sequence carries three residues in the order glycine, histidine, lysine, which places a small, flexible chain around a single metal centre. Compared with larger copper-binding proteins, the complex is compact and its coordination chemistry can be reproduced with synthetic peptide in a laboratory. Published structural work agrees on the nitrogen donor set but differs in the exact geometry assigned under some conditions, so the arrangement is best treated as well characterised in outline rather than fixed in every detail.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide was isolated from human plasma in the early 1970s by Loren Pickart, who observed that a plasma fraction from young donors stimulated growth in cultured liver cells. The copper-bound form is abbreviated GHK-Cu, while the metal-free peptide is written simply as GHK. In the research literature the complex also appears as copper tripeptide-1 and as glycyl-histidyl-lysine copper complex.
Copper(II) binds the peptide through four nitrogen donors: the terminal amino group, the imidazole nitrogen of histidine, and two deprotonated amide nitrogens of the peptide backbone. This tetradentate arrangement gives a roughly square-planar geometry, the thermodynamically favoured form near neutral pH. Because the amide nitrogens must lose a proton before they can coordinate, complex formation is strongly pH-dependent, and the fully coordinated species dominates only above mildly acidic conditions. Electronic transitions within the copper d orbital set produce the characteristic blue to violet colour in aqueous solution.
The compound was first isolated from human plasma by the biochemist Loren Pickart in 1973. Early work identified it as a factor that altered the behavior of cultured liver cells, and later studies linked it to connective tissue and wound-related processes. Reported plasma concentrations fall markedly between roughly age twenty and age sixty, a pattern that generated interest in copper peptide biology. Whether that decline has functional consequences remains an open question, because differences observed across age groups do not by themselves establish causation. Research interest later expanded into cosmetic and tissue-culture settings.
Mechanistic accounts focus on how the complex delivers copper and how the released peptide interacts with the extracellular matrix. Copper is an essential cofactor for lysyl oxidase and other enzymes involved in collagen and elastin cross-linking, and GHK is one of several peptides able to carry the metal. Reported effects include altered gene expression in fibroblasts and changes in matrix metalloproteinase activity, although many of these findings come from cell culture rather than whole organisms. The relative contribution of the peptide backbone, the copper ion, and downstream copper metabolism is not fully resolved.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-lysine and a copper(II) ion. The peptide sequence is conventionally written as Gly-His-Lys, abbreviated GHK. Copper binds through the imidazole nitrogen of histidine, the alpha-amino group, and a deprotonated amide nitrogen, producing a square-planar geometry. The complex carries a net positive charge near physiological pH and is intensely blue in aqueous solution. The metal-free peptide is often written simply as GHK, while the copper-bound form is written GHK-Cu.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II)-tripeptide complex | One peptide ligand with one coordinated metal centre |
| Peptide sequence | Gly-His-Lys | Three residues written in one-letter notation |
| Free peptide mass | 340.4 g/mol | Metal-free GHK; the complex has a higher mass |
| Appearance | Blue to violet solid or solution | Colour originates from copper d orbital transitions |
| Storage | Desiccated, -20 °C, protected from light | Dry powder is more stable than dissolved material |
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence of three amino acids. The peptide was first isolated from human plasma in 1973 during research on factors that influence tissue repair in liver. Its ability to bind copper ions became a central point of interest because the metal changes the peptide's chemistry and its behaviour in laboratory systems. Today the compound appears in cosmetic formulations, cell-culture studies, and biochemistry literature under several names.
The peptide sequence places a histidine in the middle, and this residue dominates metal binding. Copper(II) coordinates through the imidazole nitrogen of histidine and the terminal amino group, forming a stable chelate ring system. Loss of the copper ion leaves the free tripeptide, which has different solubility and reactivity. This structural detail matters because assays that measure only the peptide backbone can miss whether copper is still bound to it.
Several names circulate for the same material, which complicates literature searches. Cosmetic ingredient lists often use copper tripeptide-1, while older biochemistry papers use glycyl-L-histidyl-lysine or its abbreviation GHK. The copper complex is sometimes written as GHK-Cu(II) to make the oxidation state explicit. Terminology is not fully standardized, so matching a compound across sources requires attention to the exact sequence, the counterion, and the stated copper content. Reviews that compare studies must account for these naming differences before drawing conclusions.
GHK-Cu is the copper-binding complex formed by the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The free peptide is usually written as GHK, and the complex is written as GHK-Cu or Cu-GHK. The sequence was identified in human plasma and later detected in saliva and urine. Its name comes from the single-letter codes of glycine, histidine and lysine. The complex is widely described as a naturally occurring carrier of copper in blood rather than as a free peptide with its own hormonal role.
Copper binds to the peptide through the histidine imidazole nitrogen and the terminal amino group, forming a stable square-planar complex. Binding constants reported for copper(II) with GHK are high, so the peptide competes effectively for copper in solution. The complex absorbs visible light, which gives solutions a blue to violet colour. Whether the metal-free peptide has a distinct biological function of its own is still an open question; some work treats it mainly as a copper delivery vehicle, while other work reports peptide-specific effects.
The compound was first isolated from human plasma in the 1970s by Loren Pickart, who later described copper-binding activity in liver and other tissues. Early reports focused on its presence in blood and its ability to carry copper between proteins. Commercial and cosmetic use of the term 'copper peptide' has since broadened, and labels rarely distinguish GHK-Cu from other copper-binding fragments. This naming overlap makes literature searching harder, because cosmetic ingredient lists, supplier catalogues and laboratory papers use different vocabularies for the same molecule.
=== Ungrouped === CTDP1 CTDSP1, CTDSP2, CTDSPL DULLARD EPM2A ILKAP MDSP PGAM5 PHLPP1, PHLPP2 PPEF1, PPEF2 PPM1A, PPM1B, PPM1D, PPM1E, PPM1F, PPM1G, PPM1H, PPM1J, PPM1K, PPM1L, PPM1M, PPM1N PPTC7 PTPMT1 SSU72 UBLCP1
=== 2013–2014: First regulatory actions === In March 2013, the US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as money services businesses, subject to registration and other legal obligations. In May 2013, US authorities seized the unregistered exchange Mt. Gox. In June 2013, the US Drug Enforcement Administration seized ₿11.02 from an individual attempting to use them to purchase illicit drugs. This marked the first time a government agency had seized bitcoins. The FBI seized about ₿30,000 in October 2013 from Silk Road, following the arrest of its founder Ross Ulbricht. In December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoin. After the announcement, the value of bitcoin dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency had been illegal in China since at least 2009.
==== Knight Grand Cross of the Order of St Michael and St George (GCMG) ==== Diplomatic Service and Overseas List Sir (Arthur) John Coles, , Permanent Under-Secretary of State, Foreign and Commonwealth Office.
GnRH antagonists have an immediate onset of action leading to a fast and profound suppression of testosterone and are therefore especially valuable in the treatment of patients with prostate cancer, where fast control of disease is needed. The GnRH antagonist abarelix was withdrawn from the United States market in 2005 and is now only marketed in Germany for use in patients with symptomatic prostate cancer. Degarelix is a GnRH antagonist that is approved for use in patients with advanced hormone-sensitive prostate cancer throughout Europe and also in the United States.
Sources: en.wikipedia.org
=== Ethanol === The first historical achievement in anesthesia occurred around 4000 BC in ancient Mesopotamia. This was the advent of ethanol (commonly known as drinking alcohol), the first general anaesthetic agent. These accounts of the anesthetic uses of ethanol come from the oldest known historical civilization of Sumer and are documented in the oldest known writing system cuneiform.
Adorno's house on Seeheimer Strasse was similarly searched in July, and his application for membership in the Reich Chamber of Literature was denied on the grounds that membership was limited to "persons who belong to the German nation by profound ties of character and blood." As a "non-Aryan," he was informed, "you are unable to feel and appreciate such an obligation." Soon afterward, Adorno was forced into 15 years of exile.
=== Comparison to other staple foods === The following table shows the nutrient content of raw plantain and other major staple foods in a raw form on a dry weight basis to account for their different water contents.
Sources: en.wikipedia.org
Other studies found that, in Tanzania, skin bleaching has been regularly practiced by middle and working classes, as light skin was perceived to facilitate social mobility. Skin whitening practices in several other African countries increased following the onset of independence movements against European colonial rule. Maya Allen attributed this to the increased flow of European products and commercial influence into colonized regions. Several historians have suggested that the increased prevalence of skin whitening in "the Global South" is potentially tied to both precolonial notions of beauty and post-colonial hierarchies of race.
Bernard Sanders was born on September 8, 1941, in the New York City borough of Brooklyn. His father, Eliasz ben Yehuda Sanders, a Polish-Jewish immigrant, was born in Słopnice, a town in Austrian Galicia that was then part of the Austro-Hungarian Empire and is now in Poland. Elias Sanders immigrated to the United States in 1921 and became a paint salesman. Bernie's mother, Dorothy Sanders (née Glassberg), was born in New York City. Her parents immigrated to the United States from Radzyn, Poland, and Bialystock, Russia. Sanders says he became interested in politics at an early age due to his family background. In the 1940s, many of his relatives in German-occupied Poland were murdered in the Holocaust. Sanders lived in Midwood, Brooklyn. He attended elementary school at P.S. 197, where he won a borough championship on the basketball team. He attended Hebrew school in the afternoons and celebrated his bar mitzvah in 1954. His older brother Larry said that during their childhood, the family never lacked food or clothing, but major purchases, "like curtains or a rug", were not affordable. Sanders attended James Madison High School, where he was captain of the track team and took third place in the New York City indoor one-mile race. In high school, he lost his first election, finishing last of three candidates for the student body presidency with a campaign that focused on aiding Korean War orphans. Despite the loss, he became active in his school's fundraising activities for Korean orphans, including organizing a charity basketball game.
Lethal injection is the practice of injecting one or more drugs into a person (typically a barbiturate, paralytic, and potassium chloride) for the express purpose of causing death. The main application for this procedure is capital punishment. The drugs cause the person to become unconscious, stop breathing, and develop a heart arrhythmia, in that order. First developed in the United States, the method has become a legal means of execution in China, Thailand, Guatemala, Taiwan, the Maldives, Nigeria, and Vietnam, though Guatemala abolished the death penalty for civilian cases in 2017 and has not conducted an execution since 2000, and the Maldives has never carried out an execution since its independence. Although Taiwan permits lethal injection as an execution method, no executions have been carried out in this manner; the same is true for Nigeria. Lethal injection was also used in the Philippines until the country re-abolished the death penalty in 2006. Although primarily introduced as a more "humane" method of execution, lethal injection has been subject to criticism, being described by some as cruel and unusual. Opponents particularly critique the operation of lethal injections by untrained corrections officers and the lack of guarantee that the victim will be unconscious in every individual case. There have been instances in which condemned individuals were injected with paralytics and then with a cardiac arrest-inducing agent while still conscious; this technique has been compared to torture. Proponents often say that there is no reasonable or less cruel alternative.
Sources: en.wikipedia.org
It consists of a three-amino-acid peptide, glycine-histidine-lysine, bound to one copper(II) ion. The peptide supplies four nitrogen donor atoms, and the resulting complex is stable in neutral aqueous solution. The metal-free peptide is usually called GHK.
The three letters are the standard one-letter codes for glycine, histidine, and lysine. The suffix -Cu indicates the coordinated copper ion. Cosmetic ingredient lists often use the alternative name copper tripeptide-1 for the same complex.
No. Free GHK is the peptide alone, while GHK-Cu contains a bound copper atom. The two differ in colour, charge, and binding behaviour, so any study that measures copper delivery must state which form was used.
It is the copper(II) complex of the tripeptide glycyl-L-histidyl-lysine, a sequence of three amino acids. The copper ion is held by the histidine imidazole, the terminal amino group, and an amide nitrogen. The bound form is distinct from the free peptide in charge, color, and stability.